DAT Bio1. Molecules and Fundamentals of Biology Flashcards
(166 cards)
1
Q
any substance that takes up space and has mass is called _____
A
matter
2
Q
an ______ is a substance that has specific chemical and physical properties
A
element
3
Q
an _____ is the smallest unit of matter that still retains all the chemical properties of an element
A
atom
4
Q
can an atom break-down into something smaller, while still retaining the properties of the original element?
A
no
5
Q
molecules result whenever _____ atoms join together
A
2 or more
6
Q
_____ are molecules that contain more than one element
A
compounds
(ex: H2O is a molecule/compound)
7
Q
what are the strong attractive forces that hold atoms <i>within</i> a molecule?
A
intramolecular forces
8
Q
which type of force exists <i>between</i> molecules?
A
intermolecular forces
9
Q
which type of force (intra-/intermolecular) determines physical properties?
A
intermolecular
10
Q
_____ are molecules that have the potential of bonding to other identical molecules through chemical reactions
A
monomers
11
Q
_____ is the process when monomers bond together, and it forms _____
A
polymerization; polymers
12
Q
_____ are substances that have a large # of monomers bonded together
A
polymers
13
Q
what are the 3 varieties of carbohydrates?
A
monosaccharides; disaccharides; polysaccharides
14
Q
monosaccharides have a ratio of precisely _____ _____ per water molecule, and they have the empirical formula _____
A
1 carbon; (CH2O)n
15
Q
ribose is a _____ sugar (monosaccharide)
A
pentose (five carbon)
16
Q
glucose and fructose are _____ sugars (monosaccharides)
A
hexose (six carbon)
17
Q
glucose and fructose are _____ of each other
A
isomers
18
Q
what type of carbohydrate results when 2 monosaccharide monomers bond/join together?
A
disaccharide
19
Q
monosaccharide monomers join together via what type of reaction?
A
dehydration/condensation reactions
20
Q
what type of bond is formed and what is released in a dehydration/condensation reaction?
A
covalent bond formation; release of H2O
21
Q
what is the opposite of a condensation/dehydration reaction - why?
A
A hydrolysis reaction; adds H2O to a covalent bond and splits monomers apart
22
Q
what is the name of the bond that forms when a carbohydrate attaches to another molecule?
A
glycosidic
23
Q
which disaccharide contains 1 glucose and 1 fructose?
A
sucrose (table sugar)
24
Q
which disaccharide contains 1 galactose and 1 glucose?
A
lactose
25
which disaccharide contains 2 glucoses linked together?
maltose
26
polysaccharides are long polymers of _____
monosaccharides
27
_____ may or may not have branching
polysaccharides
28
some polysaccharides are for _____, and others are for _____
storage, structure
29
_____ is a crucial storage polysaccharide in plants
starch
30
starch contains many _____ monomers in linear forms as well as branched forms
glucose
31
linear plant starch is called _____
amylose
32
what is amylopectin?
branched form of plant starch
33
_____ is a storage polysaccharide found in humans
glycogen
34
glycogen contains many _____ monomers
glucose
35
is amylopectin or glycogen more branched?
glycogen
36
what type of bonds does glycogen have?
α-1,4-glycosidic (linear); *many* α-1,6-glycosidic (branches)
37
name two alpha-glucose polysaccharides
starch (ex. amylose, amylopectin); glycogen
38
_____ is a structural polysaccharide found in plant cell walls, wood, and paper
cellulose
39
cellulose is a _____ polymer
glucose
40
what type of bonds does cellulose contain - what do they do?
β-1,4-glycosidic bonds; allows cellulose to form linear strands that pack together in parallel
41
cellulose has high ____ due to its structure
rigidity
42
chitin is a _____ polysaccharide
structural
43
chitin is found in the cell walls of _____ and in the exoskeletons of ____
fungi; insects
44
chitin is a structural polysaccharide with _____ added to each monomer
Nitrogen
45
what type of bonds are in chitin?
β-1,4-glycosidic
46
proteins contain polymers called _____, and each of these polymers contain monomeric subunits called ______.
polypeptides; amino acids
47
in an amino acid, what 4 things is the central (alpha) carbon bonded to?
hydrogen atom (H), amino group (NH2), carboxyl group (COOH), and an "R group"
48
how many amino acids are there?
20
49
amino acids in a polypeptide are linked together via a covalent bond called a ______ bond
peptide
50
how do amino acids form peptide bonds with one another?
dehydration/condensation reactions
51
which type of reactions separate the amino acids of a polypeptide?
hydrolysis
52
polypeptides have an _____ terminus and a _____ terminus
amino (N-); carboxyl (C-)
53
the _____ structure of a protein is its amino acid sequence
primary
54
all proteins have _____ structure
primary
55
the _____ structure of a protein are folds that occur in a polypeptide chain due to intermolecular forces between atoms of the polypeptide backbone
secondary
56
the _____ is the amino acid structural features other than the R-group
polypeptide backbone
57
does the secondary structure include interactions between R-group atoms?
no
58
which level of protein structure includes alpha helices and beta-pleated sheets?
secondary
59
the _____ structure is the 3D structure of larger polypeptide chains due to (usually) non-covalent interactions between amino acid R-groups
tertiary
60
what are the common interactions between R-groups in tertiary structure?
ionic bonding; hydrogen bonding; dipole-dipole interactions; London dispersion (van der Waal) forces; hydrophobic interactions; disulfide bonding
61
usually tertiary structures involve non-covalent interactions; however, ______ bonds are the "covalent exception"
disulfide
## Footnote
(these are covalent)
62
which amino acids allows disulfide bond formation?
cysteine
63
the _____ structure refers to large proteins that have multiple subunits (i.e. contain multiple polypeptide chains)
quaternary
64
while there are multiple polypeptide chains in a quaternary structure, the entire structure is considered to be _____
1 protein
65
_____ causes proteins to lose their secondary, tertiary, and quaternary structures
protein denaturation
66
denatured proteins retain their _____ structure
primary
67
loss of _____ leads to a loss of protein function
shape
## Footnote
(denaturation)
68
what are some causes of protein denaturation?
excess temperature, chemicals, pH changes, radiation
69
_____ are molecules that increase reaction rates
catalysts
70
despite speeding up reactions, catalysts do not affect the _____ of a reaction
spontaneity
71
_____ are not used up by the reactions they manipulate, meaning the reaction does not change them
catalysts
72
catalysts lower _____ to speed reactions
activation energies/transition state energies
73
_____ do not change energy absorbing reactions to energy releasing ones, or vice versa
catalysts
74
catalysts do not affect the energy of _____ or _____
reactants; products
75
_____ are biological protein catalysts
enzymes
76
substrates bind to enzymes at the _____ (location)
active site
77
the _____ measures how efficient an enzyme is in converting substrate to product
specificity constant
78
enzymes bind at the active site via the _____ model
induced fit
79
not all enzymes are proteins - give an example of an RNA enzyme:
ribozymes
80
______ are non-protein molecules that assist enzymes
cofactors
81
________ are organic cofactors (e.g. vitamins)
coenzymes
82
inorganic cofactors are usually _____
metal ions
## Footnote
e.g. iron (Fe2+) or magnesium (Mg2+)
83
_____ refer to enzymes that are bound to their cofactor
holoenzymes
84
what is an apoenzyme?
an enzyme that is lacking (not bound to) its cofactor
85
cofactors that tightly/covalently bind to their enzyme in a holoenzyme are known as _____
prosthetic groups
86
Protein enzymes have optimal _____ and _____ ranges in which they have the highest enzymatic activity.
pH; temperature
## Footnote
(temperature ranges at the upper end of a normal physiological range generally increase enzyme function)
87
_____ is a form of enzyme regulation, where inhibitors compete with substrates for active sites
competitive inhibition
88
we can outcompete a competitive inhibitor by adding more _____
substrate
89
what is enzyme saturation?
all active sites are occupied
90
_____ is when an inhibitor binds to the allosteric site of an enzyme
noncompetitive inhibition
91
what is an allosteric site?
a different location that is not the active site of enzyme catalysis
92
a noncompetitive inhibitor binding to the allosteric site modifies the _____ so that the substrate has reduced binding or cannot bind
active site
93
we cannot _____ allosteric inhibitors by adding more substrate
outcompete
94
the rate of enzyme catalysis is unaffected by increasing the substrate concentration in _____ inhibition
noncompetitive
95
_____ is the substrate concentration [X] at which the velocity is 50% of the Vmax
Michaelis Constant (Km)
96
a _____ Km indicates that Vmax is reached at low substrate concentrations because enzyme ability/function is high
small
97
a _____ Km indicates that Vmax is reached at high substrate concentrations because enzyme availability/function is low
large
98
in competitive inhibition, Km increases and Vmax _____
remains the same
99
this enzyme cleaves a phosphate group off of a substrate molecule
phosphatase
100
this enzyme adds a phosphate group to a substrate molecule using inorganic phosphate
phosphorylase
101
this enzyme transfers a phosphate group from an ATP molecule to a substrate molecule.
kinase
102
in noncompetitive inhibition, Km stays the same and Vmax _____
decreases
103
lipids are _____, non-polar molecules, meaning they do not mix well with water
hydrophobic
104
what are the components of a triglyceride?
three fatty acid chains attached to a glycerol backbone
105
what type of bonds exist between glycerol/fatty acids in a triglyceride?
ester linkage
106
_____ fatty acids have no double bonds
saturated
107
saturated fatty acids pack _____
tightly
108
saturated fatty acids tend to be _____ at room temperature
solid (think of butter)
109
_____ fatty acids can possess 1 (or more) double bonds
unsaturated
110
_____ fatty acids have 1 double bond
monounsaturated
111
_____________ fatty acids have 2 or more double bonds
polyunsaturated
112
cis-unsaturated fatty acids create _____ in the fatty acid chain, meaning they do not pack tightly
kinks
113
trans-unsaturated fatty acids pack together _____, and they are very bad for health
tightly
114
_____ are a unique type of lipid (fat) found in cell membranes
phospholipids
115
what are the components of a phospholipid?
a three-carbon glycerol backbone attached to 1 phosphate group and 2 fatty acid tails
116
phospholipids are _____, meaning they have both hydrophobic and hydrophilic properties
amphipathic
## Footnote
(the phosphate group is polar and hydrophilic; the fatty acids are non-polar and hydrophobic)
117
_____ are like phospholipids but with a carbohydrate group rather than a phosphate group
glycolipids
118
cell membranes form through spontaneous _____ of phospholipids into a bilayer
self-assembly
119
cholesterol contains _____ hydrocarbon rings and is also amphipathic
four
120
what are the factors that modulate membrane fluidity?
temperature; cholesterol; degree of unsaturation in the phospholipid fatty acid tails
121
what maintains membrane fluidity in the cold?
increasing phospholipid unsaturation; cholesterol
122
what maintains membrane fluidity in the heat?
decreasing phospholipid unsaturation; cholesterol
123
cholesterol is a starting material for vitamin _____ and a precursor to _____ acids
D; bile
124
_____ is the most common steroid precursor
cholesterol
125
lipids are insoluble and must be transported through the blood in structures called _____
lipoproteins
126
lipoproteins contain a _____ of phospholipids, cholesterol, and proteins
coat
127
_____ (lipoproteins) have a low density of proteins and are generally considered unhealthy
low-density lipoproteins (LDLs)
128
_____ (lipoproteins) have a high density of proteins and are generally considered to be healthy
high-density lipoproteins (HDLs)
129
waxes & carotenoids are _____ derivatives
lipid
130
______ contain esters of fatty acids and monohydroxy alcohols
waxes
131
waxes are often used as a _____, protective coating
hydrophobic
132
describe the general structure of a carotenoid:
long carbon chains with conjugated double bonds and 6-membered rings at each end
133
describe the general function of a carotenoid:
they function as pigments, which produce colors in plants and animals
134
describe the general structure of a sphingolipid:
sphingoid base backbone composed of a set of aliphatic (non-aromatic) amino alcohols
135
describe the general function of a sphingolipid:
membrane structural integrity, signal transduction and cell recognition
136
what are 2 common nucleic acids to know?
DNA; RNA
137
_____ have a pentose sugar attached to a nitrogenous base
nucleosides
138
a _____ is a pentose sugar attached to a nitrogenous base and a *single* phosphate group
nucleotide
139
nucleic acids are polymers made of _____
nucleotides
140
what are the 4 possible bases of a DNA nucleotide?
adenine, thymine, cytosine, guanine
141
what are the 4 possible bases of a RNA nucleotide?
adenine, uracil, cytosine, guanine
142
What are polymers made of?
nucleotides
143
What are the 4 possible bases of a DNA nucleotide?
adenine, thymine, cytosine, guanine
144
What are the 4 possible bases of an RNA nucleotide?
adenine, uracil, cytosine, guanine
145
Nucleotides can be further categorized depending on their nitrogen base as a _____ or _____?
purine; pyrimidine
146
Nitrogenous bases that are _____ have 2 rings.
purines
147
Nitrogenous bases that are _____ have 1 ring.
pyrimidines
148
Adenine and Guanine have 2 rings and are classified as _____?
PURines
## Footnote
(PUR As Gold)
149
Cytosine, Uracil, and Thymine have 1 ring and are classified as _____?
pyrimidines
## Footnote
(CUT the PY)
150
_____ groups attach to the nucleotide sugar at the 5' carbon.
phosphate
151
5' _____ of one nucleotide connect to the 3' _____ of another nucleotide in nucleic acids.
phosphates; hydroxyl
152
Bonding between a 5' phosphate and a 3' hydroxyl forms a _____ bond in nucleic acids, creating the sugar-phosphate backbone.
phosphodiester
153
Nucleic acids have _____, with a 5' and 3' end.
directionality
154
_____ add to growing nucleic acid polymers.
nucleoside triphosphates
155
DNA manifests as a _____, _____ helix.
antiparallel; double-stranded
156
Purines can only hydrogen bond to _____?
pyrimidines
157
Pyrimidines can only hydrogen bond to _____?
purines
158
Adenine and thymine (or uracil) pair together via _____ hydrogen bonds.
2
159
Cytosine and guanine pair together via _____ hydrogen bonds.
3
160
Unlike DNA, RNA is usually _____ stranded.
single
161
What are the fundamental statements of the modern cell theory?
1. All lifeforms have one or more cells
2. The cell is the basic structural, functional, and organizational unit of life
3. All cells come from other cells (cell division)
4. Genetic information is stored and passed down through DNA
5. An organism's activity is dependent on the total activity of its independent cells
6. Metabolism and biochemistry (energy flow) occurs within cells
7. All cells have the same chemical composition within organisms of similar species
162
Does the cell theory apply to viruses?
no - they are not considered living cells
163
The central dogma of genetics states that information flows from _____ to _____ to _____?
DNA; RNA; proteins
164
An exception to the central dogma of genetics are _____ and _____?
reverse transcriptase; prions
165
What is the hypothesis for the creation of the first cell as we know it?
the RNA world hypothesis
166
The RNA world hypothesis suggests that self-replicating _____ molecules were the precursor to current life.
RNA
